Filtering cistern or vat



(No Model.)

C. C. GILMAN.

FILTERING GIS'I'ERN 0R VAT.

No. 341,649. Patented Ma Wt# j' 7 UNITED STATES APATENT OFFICE.,

CHARLES CARROLL GILMAN, OF ELDORA, IOIVA.

FILTERING CISTERN OR VAT.

SPECIFICATION forming part of Letters Patent No. 341,649, dated May ll,1896.

n Application filed December 1l, i884. VSerial No. 150,128. (No model!)c eistern and a reservoir,containing my invention.

Fig. 2 is a plan view of several contiguous tltering-cisterns located atthe margin of a stream of water, with conduits leading from the streamto the cisterns, together' with a common reservoir, into which all thecisterns empty. Fig. 3 is a sectional view of the Sallie, and Fig. 4 isa front elevation of the cistern.

This invention relates to cisterns or vats for filtering liquids, thesame being specially adapted to the iltering of water on alarge scalefor the use of cities or villages; and it consists in cisterns or vatshaving the peculiar construction and formed of the material hereindescribed and claimed.

My filtering-cisteru is constructed as follows: rIhe walls and bottom Imake of brick or stone laid in cement, so as to be watertight. The topmay be open. I then lay upon the bottom a number of joists, which arepreferably about three by six inches in cross-section, laid on theiredges and extending lacross the cistern. Thesejoists or supports may beot' wood, but preferably,i`or durability and cleanliness, they are ofbrick or terra-cotta. Upon these snpports I lay a false bottom Aformedof porous terra-cotta slabs from two to three inches in thickness, andextending between and resting upon the supports, the abutting edgesbeing cemented together, so as to form water-tight joints. A falsebottom supported in any other `way may be used, but the manner describedwill be found to be preferable. The porous terra-cotta used for thispurpose is produced by mixing sawdust with the clay of whichtheterra-cotta is made, which in the firing is burned out, leaving theterra-cotta porous, as described in United States Reissued LettersPatent Nos. 10,419 and 10,420, granted to me December 11, 1883.

One of the side walls of the cistern is pierced with openings on a levelwith the bottom and y from the cistern into the reservoir E.

below the said false bottoni between the `=sev eral joists or supports,for the escape of the water after iltration.

My storing vat or reservoir, adapted to receive the water as it escapesfrom the lteringcistern, -is a simple water-tight inclosure of suitablesize to hold the quantity of water which it. is desired to store. Itswalls are preferably' formed of brick or stone cemented together. It islocated relatively to the cistern so that its top is on a level with thebottom of the Gistel-11,01 nearly so, in order that the water as itissues from the cistern may tlow naturally into and ll the reservoir.

In the drawings, A represents the illeringcistern,

O represents the joists or supports laid on the bottom A of the cistern,and l) the false porous terracotta bottom resting on the said Supports.`Y

E represents the storing vat or reservoir,

placed in the proper position relatively to the i cistern, and btheopenings in the front wall of g5 the ciste-rn, through which thewaterescape For the purpose of rendering the process of filtering moreperfect, I spread upon the de-i scribed false bottom D a layer of coarseclean gravel, preferably about six inches thick, and upon the gravel Ispread an equal layer ot' p ure sand. The water in percolating throughthe false bottom alone will usually leave its impurities wholly or ingreat measure in the porous terra-cotta; but the gravel and sandA willgreatly aid the filtering process. The said false bottom ot' porousterra-cotta, in this connection, performs two functions, namely: It actsas au indestructible support for the loose ltering material placedthereon, and also acts as a iilter to iilter the water passingtherethrough after having passed through the sand and gravel.

When the filtering material has become nnduly loaded with impurities,the sand and gravel (if they are employed) may be removed and a newsupply laid in.

To cleanse the false bottom itself, it is only necessary to take up andturn over the blocks of terra-cotta, when the water, in percolatingthrough them, will force the deposited. im puri- IOO jacentstorage-reservoir, may be located by the margin of a stream from whichthe supply for a city or town is obtained, and the water from the streamled directly into the cistern through a suitable conduit. In such easethe cistern is sunk in the ground to below the level ofthe surface ofthestream and the reservoir sunk to a still lower level.

It is preferable to construct several separate or adjoiningltering-cisterns, which may all disehargeinto one and the samestoragereservoir. Fig. 2 represents such an arrangement. A A A representthese cisterns located by the margin of a stream, G, the same being sunkin the ground H below the surface of the stream. E is the reservoir,also sunk in the ground, with its top about on a-level with the bottomof the cistern. a a a are conduits leading from the stream to theoisterus, and b b b conduits leading from the cisterns to the reservoir. By suitable gates (not shown) connected with these conduits thewater may be shut off from either cistern at pleasure, so that one ormore ofv the cisterns may be cleansed,

' while the other or others may be kept in operation.

When the source ot' the water-supply will permit it, or where artificialmeans are einployed to raise the water into the filteringcistern, it isnot of course essential that the cistern should be sunk in the ground.It may be placed onor above the ground, with the storage-reservoirlocated relatively to it, as described.

The use of the described filtering-cist-ern is not of course limited tothe filtering of water. lt may be employed to filter other liquids, suchas oils, sii-ups, Ste.

The cistern, as well as the storage-reservoir which I have described,may be of any desired dimensions adapted to the quantity of liquid 1t isdesired to vfilter in a given time.

I am aware that ithas been proposed to construct a eistern with a falsebottom composed of ordinary brieks,through which the water is filtered,as shown in Patent No. 100,323, to B. B. Redfield; but thisIdo notclaim, for the ordinary brick is too dense to permit the rapid ltrationof the water therethrough.

I am aware that a bed of sand has been placed upon a sheet of'perforated metal or wire-cloth, as described and shown in patent toJ.V.Hyatt, No. 27 3,539, March 6,1883; also, that loose filteringmaterial has been placed upon aperforated metal plate; but 'theseconstructions differ materially from my invention in tworespects-rst,beeause I substitute for the iron support a material whichcannot rust o1' decay, and will last a greatly longer time than-iron asa support for the loose ltering material; and, second, because my porousterra-cotta support acts to purify the water passing therethrough,retaining much impurity that may not have been eliminated by thesuperimposed layer of loose filtering material. A perforated iron plateor wire-cloth supportinga loose filtering material performs no filteringfunctions, since the openings therein are much larger than theinterstices between the particles of the loose filtering material. Sucha support serves merely to allow the passage of filtered water-4. e.,the Water filtered by the superimposed filtering material. I do notclaim a support which is astrainer or filter in thev broadest sense inwhich those terms can be used, but only in the sense that it can removethe finer impurities. A wire-cloth support by itself cannot eliminatethese finer impurities, but serves only to prevent the passage ot'sticks and other relatively large foreign bodies.

Vlbat I claim as my invention, and desire to secure by Letters Patent,is-

l. A filtering cistern or receptacleprovided with a false bottom ofporous terra cotta, aet- Ving as a filtering means, as described, andwith loose filtering material resting on and supported by said bottom,substantially as described.

2. A ltering cistern or receptacle provided with a false bottom ofporous terracotta, aeting as a filtering means, as described, and withlayers of gravel and sand supported by said bottom, substantially asdescribed.

CHARLES CARROLL GILMAN.

Vitnesses:

HENRY M ARKELL, A. G. N. VERMILYA.

